298 Miscellaneous. 



cannot here do more than give a very brief summary of the principal facts de- 

 tailed, without making any reference to the authorities to whom the Doctor refer- 

 red, but which will of course be mentioned in the report This report was read in 

 three portions, on three separate mornings, but we prefer giving the whole of it 

 together, as though it had occupied only one sitting. With this exception, the 

 proceedings of the Section will be referred to the several days on which they 

 took place. 



Monday, August 22rf. — Dr Richardson's Report. 

 Notwithstanding the ravages which have taken place among the various tribes 

 of animals in North America, as the progress of civilization has advanced from 

 east to west, it is still highly probable that no single species has yet become 

 extinct, and the colonist has still the means within his reach of studying the ha- 

 bits of every indigenous animal. As the genera of European and North Ame- 

 rican animals are for the most part the same, whilst a very great dissimilarity 

 subsists between the species peculiar to the two continents, this affords consi- 

 derable facility for promoting inquiries into the geographic distribution of par- 

 ticular types of animals. The observations of Dr Richardson in this report were 

 confined to the distribution of the Mammalia and Aves ; and chiefly those which 

 were inhabitants of the western parts of North America, including New Mexico, 

 the Peninsula of Florida and California, down to the well-defined limits of the 

 South American zoological province. Dr Richardson then entered at consider- 

 able length into the description of the physical structure of the country under 

 consideration, pointing out the more direct means of communication by trans- 

 verse valleys, the course of streams, or extensive prairie lands, along which the 

 quadrupeds, birds, or fish of distinct parts were enabled to perform their re- 

 spective migrations; and he stated the great probability of a more complete in- 

 terchange of the fish one day occurring, so soon as the several canals already 

 projected, or in progress, should be completed. The eastern coast, at least in the 

 more northern latitudes, has a decidedly lower mean temperature than the west- 

 ern, or than that of the eastern parts of Europe under the same parallels of lati- 

 tude. In consequence of this, the migration of the birds is here more general 

 than under the same parallels in Europe. Dr Richardson then entered upon 

 several details connected with the subject of temperature. 



Geographic Distribution of the Mammalia — Although there exists a great ge- 

 neral similarity between the Mammalia of Europe and North America, these lat- 

 ter are widely different from those of the southern Fauna of the new world. 

 The line of demarcation between these zoological provinces does not occur at 

 the Isthmus of Darien, but at the tropic of Cancer. Dr Richardson then de- 

 tailed the particular results of his inquiries under the several orders of this class, 

 from which we cull the following remarks as among the most interesting. 



Quadrumana Although one species of this order is found in Europe as far 



north as latitude 36°, none occur in America to the north of the Isthmus of 

 Darien. 



Carnivora — The sixteen bats of North America are peculiar, but in all pro- 

 bability there are many more to be discovered. Only two of them have been 

 yet traced over any great extent of country. 



There are ten species of Insectivora, and in this family the North American 

 Mammalia differ more from the European than in any other of the Carnivora. 

 There are three European genera, which do not exist in North America, and the 



